type ints = {sum: ~int, values: ~[int]}; fn add_int(x: &mut ints, v: int) { *x.sum += v; let mut values = ~[]; x.values <-> values; values.push(v); x.values <- values; } fn iter_ints(x: &ints, f: fn(x: &int) -> bool) { let l = x.values.len(); uint::range(0, l, |i| f(&x.values[i])) } fn main() { let mut ints = ~{sum: ~0, values: ~[]}; add_int(ints, 22); add_int(ints, 44); for iter_ints(ints) |i| { error!("int = %d", *i); } error!("ints=%?", ints); }